Acute myocardial infarction after radiofrequency catheter ablation of typical atrial flutter: histopathological findings and etiopathogenetic hypothesis.

The right atrial inferior cavotricuspid isthmus represents the targeting site for radiofrequency (RF) current application during ablation treatment of typical atrial flutter. Despite the vicinity of the right coronary artery (RCA) to the RF application site and the long energy exposure needed to achieve electrophysiological success, reports about direct thermal damage of the coronary vessel during ablation of the cavotricuspid isthmus are rare and anecdotal. The present is the first case report describing the cardiac macroscopic and histological examination in a patient who died of cardiac rupture, as a complication of a myocardial infarction occurring after a standard procedure of RF ablation of typical atrial flutter. In consideration of the proximity we found between the RF energy-dependent tissue damage and the RCA, thermal-related damage of RCA during ablation of typical atrial flutter should always be considered as a potentially harmful risk of the procedure.     

Acute right coronary artery occlusion following radiofrequency catheter ablation of atrial flutter

Acute right coronary artery occlusion following radiofrequency ablation. We report the first known case of acute right coronary artery occlusion following Radiofrequency (RF) ablation for atrial flutter in a patient without known prior coronary disease. Our patient developed acute chest pain and inferior ST-segment elevation immediately following the procedure. Emergent cardiac catheterization was performed, revealing an occluded distal right coronary artery, which was immediately stented. Acute coronary occlusion should be considered in the differential diagnosis of patients, with or without coronary artery disease, who experience chest pain following RF ablation for atrial flutter.     

Invasive Elektrophysiologie: Komplikationen, Alpträume und deren Management

Most minor side effects of ablation in the right atrium and right ventricle relate to femoral venous catheterization but there is a small risk of severe complications including atrioventricular (AV) block, damage of surrounding structures and thromboembolic events. Impairment of AV conduction can occur during ablation of atrioventricular re-entrant tachycardia, ablation of anteroseptal, mid-septal and parahisian accessory pathways, ablation of ectopic atrial tachycardia originating from the vicinity of the atrioventricular node and when ablating the septal isthmus for typical atrial flutter. Damage of the right coronary artery is a very rare complication after inferior isthmus ablation with high energy. The thromboembolic risk during and after cardioversion and ablation of atrial flutter is higher than previously recognized and anticoagulation therapy decreases this risk. The risk of perforation and tamponade during ablation in the right atrium and right ventricle is very low but particular caution is necessary in thin-walled structures such as the coronary sinus and the upper right ventricular outflow tract. Phrenic nerve injury can be avoided by pacing from the mapping electrode before application of radiofrequency energy at the right atrial free wall. Limitation of power output depending on the site of ablation and titration of energy application with continuous control of temperature and impedance should be considered to minimize the risk of complications.     

Dual-loop intra-atrial re-entry tachycardia in a patient with ischaemic cardiomyopathy.

A 65-year-old man with ischaemic cardiomyopathy (three prior coronary artery bypass surgery procedures), underwent catheter ablation for recurrent atrial flutter. Electrophysiological study initially revealed clockwise, tricuspid annulus/inferior vena cava isthmus dependent, atrial flutter. During radiofrequency energy ablation atrial flutter changed into a different atrial tachycardia without change in cycle length or interruption of the tachycardia. The new tachycardia was a right atrial free wall re-entry tachycardia. Thus the two atrial tachycardias formed a dual-loop ('figure-of-eight') re-entry circuit, possibly due to atrial scar tissue from multiple cardiac surgery procedures.     

射频消融治疗心房扑动

目的总结典型心房扑动的射频消融治疗经验。方法56例因反复心悸的住院患者,男性38例,女性18例,平均年龄(54.2±6.2)岁。体表心电图及动态心电图记录阵发心房扑动34例,持续心房扑动22例,口服胺碘酮治疗效果差。全部病例常规取右股静脉途径插入20极环状Halo电极记录心房激动顺序,4极电极送至冠状窦供起搏标测使用。结果全部手术成功。其中36例心房扑动于射频发放过程中终止,20例于窦性心律下放电消融。所有病例于消融结束后分别起搏冠状窦近端和低位右心房,证实峡部双相传导阻滞作为消融终点,即刻成功率100%。平均随访(6±2.6)个月,3例于术后2个月复发,复发率5.4%,经再次射频消融治疗成功,随访6个月,未再复发。结论以温控射频导管不间断放电线性消融治疗典型心房扑动疗效肯定,成功率高。     

低右房电图极性改变评价典型心房扑动射频消融结果

目的　在典型心房扑动 (房扑 )射频消融中观察临近峡部的低位右房心内电图极性改变 ,来迅速判断是否形成峡部双向阻滞。方法　对 10例典型房扑患者 ,沿三尖瓣环放置Halo电极 ,Halo远端紧邻峡部消融线 ,房扑发作中消融在房扑终止后行冠状窦起搏 ,窦性心律下消融则同时行冠状窦电极起搏 ,观察紧邻消融线低右房侧的心房电极电图起始部分的主波方向 (H电位 )的极性表现 ,并与最终双向阻滞评价结果比较。结果　 8例在窦性心律下行冠状窦电极起搏时消融 ,2例在房扑发作中消融。 10例患者最终消融结果均为双向阻滞。 2例房扑发作时H电位极性均为负向 ,8例窦性心律下H电位极性均为正向 ,峡部缓慢传导时该极性仍为正向 ,形成双向阻滞后H电位极性变为负向。结论　典型心房扑动行峡部线性消融时 ,行冠状窦起搏观察到紧邻峡部消融线低右房侧H电位的极性改变可能是峡部消融成功的新指标。该指标简单、快速、可靠性高。     

Type I Atrial Flutter Ablation Guided by a Basket Catheter

Atrial Flutter Ablation. Bidirectional isthmus conduction block has been associated with a low recurrence rate after atrial flutter ablation. We present the ease of a type I, typical or "counterclockwise" atrial flutter ablation guided by stimulation and recordings obtained from a basket catheter, which allowed for constant electrogram recording from splines positioned along the right lateral free wall and septum. After atrial flutter termination with radiofrequency application, the ability to record and stimulate from multiple sites in the atrium using the basket catheter was useful to detect residual bidirectional slow conduction through the isthmus. Complete isthmus block could be documented after additional radiofrequency energy applications.     

射频消融心房扑动拖带刺激的电生理特征

探讨射频消融心房扑动 (简称房扑 )拖带刺激的电生理特征 ,更好的理解房扑机制 ,以期提高消融成功率、减少复发率。 5例阵发性典型房扑患者 ,诱发房扑后 ,在高位、低位右房 ,冠状窦口 (CSO)及右房下部的峡部分别进行拖带刺激 ,分析心房激动顺序 ,然后进行三尖瓣环至下腔静脉之间的线性消融。 5例房扑折返环均为逆钟向旋转 ,峡部 ,高位、低位右房及CSO呈现隐匿拖带 ,左房和卵圆窝呈现显性拖带 ,平均放电 9± 6次 ,均达到右房峡部双向阻滞。CSO起搏时体表心电图Ⅱ、Ⅲ、aVF导联P波形态发生改变。结论 :隐匿、显性拖带对判断峡部依赖性逆钟向房扑有较高价值 ,CSO起搏时心内电图激动顺序和体表心电图P波改变可做为判断峡部消融达到双向阻滞的标志     

Radiofrequency catheter ablation for the treatment of human type 1 atrial flutter. Identification of a critical zone in the reentrant circuit by endocardial mapping techniques.

BACKGROUND. Recent studies of human type 1 atrial flutter demonstrated reentry in the right atrium and an area of slow conduction in the low posteroseptal right atrium. Direct-current catheter ablation of this area has been only moderately successful in preventing recurrence. Therefore, we performed endocardial activation mapping and entrainment pace mapping during atrial flutter to determine the critical site for radiofrequency ablation of this arrhythmia. METHODS AND RESULTS. Twelve consecutive patients (seven men and five women; age, 21-73 years) with type 1 atrial flutter (mean cycle length, 253 +/- 39 msec) underwent right atrial endocardial activation and entrainment pace mapping using standard transvenous catheter techniques to localize the atrial flutter reentrant circuit, the area of slow conduction, and the exit site from the area of slow conduction. Upon identifying appropriate sites, radiofrequency energy (16-29 W) was applied via a 4-mm tipped catheter. Activation mapping of atrial flutter revealed a counterclockwise reentrant wave front originating just inferior or posterior to the coronary sinus ostium, proceeding superiorly in the atrial septum to the right atrial free wall, then inferiorly toward the tricuspid annulus and finally medially between the inferior vena cava and the tricuspid annulus, where low-amplitude fragmented electrical activity was noted. Entrainment pace mapping from this area produced an exact P wave match to atrial flutter on 12-lead ECG with a long (greater than 40 msec) stimulus-to-P interval indicating slow conduction, whereas pacing just inferior or posterior to the coronary sinus ostium produced an exact P wave match with a short stimulus-to-P interval (less than 40 msec), presumably identifying the exit site from the area of slow conduction. Radiofrequency energy (one to 14 applications) was effective in terminating and preventing reinduction of atrial flutter in 10 patients. In two patients, atrial flutter was not terminated during radiofrequency energy application but during subsequent pacing attempts. Sites where ablation was successful, located just inferior or posterior to the coronary sinus ostium, were characterized by discrete electrograms with activation times of -20 to -50 msec before P wave onset and exact entrainment pace maps with a stimulus-to-P interval of 20 to 40 msec, consistent with the exit site from the area of slow conduction. Follow-up (mean, 16 +/- 9 weeks; range, 2-31 weeks) revealed recurrence of the original atrial flutter in two patients, one of whom underwent repeat ablation without further recurrence, self-limited infrequent recurrence of a new atrial flutter or atrial fibrillation in three suppressed by beta-blocker or digoxin, and no recurrence in seven. CONCLUSIONS. 1) Radiofrequency energy applied to a critical area in the atrial flutter reentrant circuit, inferior or posterior to the coronary sinus ostium, will terminate and prevent arrhythmia reinduction. 2) Long-term follow-up in a larger series of patients will be required to confirm efficacy of this technique, although short-term results look promising.     

对比观察射频消融右房后位峡部和间隔峡部治疗典型心房扑动的疗效

对比观察射频消融右房后位峡部和间隔峡部治疗心房扑动 (简称房扑 )两种方法的疗效。 41例房扑患者随机分为后位峡部组 ( 18例 )和间隔峡部组 ( 2 3例 ) ,消融线径分别为三尖瓣环—下腔静脉和三尖瓣环—欧氏嵴。成功消融终点为房扑不能诱发和峡部呈完全性双向阻滞。结果 :40例消融成功 ( 97.6 % ) ,无并发症。后位峡部组 3例和间隔峡部组 2例在首选消融方法失败后 ,改用另一种消融方法获得成功。两组患者的放电次数和手术时间均无显著性差异。平均随访 12 .4± 6 .8个月 ,在后位峡部消融成功者中 ,有 2例房扑复发。结论 :射频消融右房后位峡部和间隔峡部治疗房扑均安全有效 ,两种方法互补可以提高消融的成功率     

Electrophysiologic Characteristics and Radiofrequency Catheter Ablation in Patients with Clockwise Atrial Flutter

RF Catheter Ablation of Clockwise Atrial Flutter. introduction: Although the mechanism and radiofrequency catheter ablation of counterclockwise (typical) atrial flutter have been studied extensively, information about the electrocardiographic and electropbysiologic characteristics and effects of radiofrequency ablation in patients with clockwise atrial flutter is limited. Methods and Results: Thirty consecutive patients with clinically documented paroxysmal clockwise atrial flutter were studied. Endocardial recordings and entrainment study using a “halo” catheter with 10 electrode pairs in the right atrium were performed. Radiofrequency energy was applied to the inferior vena cava-tricuspid annulus (IVC-TA) and/or coronary sinus ostium-tricuspid annulus (CSO-TA) isthmus to evaluate the effects of linear catheter ablation. Eighteen patients had both counterclockwise and clockwise atrial flutters, and 12 patients had only clockwise atrial flutter. Both forms of atrial flutter had similar flutter cycle lengths (232 ± 30 vs 226 ± 25 msec, P = 0.526) but reverse activation sequences. Right atrial pacing at a cycle length 20 msec shorter than the flutter cycle length from the CSO-TA isthmus, IVC-TA isthmus, and the area between the two isthmuses revealed concealed entrainment with stimulus-to-P wave intervals of 32 ± 19, 95 ± 14, and 50 ± 17 msec (P = 0.022) in the counterclockwise form, and 110 ± 12, 40 ± 20, and 60 ± 15 msec (P = 0.018) in the clockwise form. In clockwise atrial flutter, 20 patients with biphasic P waves in the inferior leads had the presumed exit site of slow conduction area located at the low posterolateral right atrium; 10 patients with positive P waves in the inferior leads had the presumed exit site located at the mid-high posterolateral right atrium. Among the 18 patients with both forms of atrial flutter, linear ablation lesions directed at the IVC-TA isthmus eliminated both forms of atrial flutter in 14 patients; in the remaining 4 patients. CSO-TA linear lesions eliminated the counterclockwise form and IVC-TA lesions eliminated the clockwise form. Among the 12 patients with the clockwise form only, CSO-TA linear lesions eliminated flutter in 2 and IVC-TA linear lesions eliminated flutter in 10 patients. Successful ablation was confirmed by creation of bidirectional conduction block in the IVC-TA and/or CSO-TA isthmus during pacing from the proximal coronary sinus and right posterolateral atrium sandwiching the linear lesions. During the follow-up period of 17 ± 8 months, 2 patients had recurrence of clockwise atrial flutter, 1 patient had new onset of atypical atrial flutter, and 2 patients had new onset of atrial fibrillation. Conclusions: Counterclockwise and clockwise atrial flutters may have overlapping slow conduction areas with different exit sites. Radiofrequency catheter ablation using the linear method directed at the IVC-TA and CSO-TA isthmuses was feasible and effective in treating both forms of atrial flutter.     

Management of atrial flutter

Typical atrial flutter is a macroreentrant arrhythmia of the right atrium. The isthmus area between the tricuspid annulus, the inferior vena cava, and the ostium of the coronary sinus is a critical zone of the reentry circle. Atrial flutter has been treated with class I and III antiarrhytmic drugs to maintain sinus rhythm, with moderate success. Catheter ablation has been highly successful in treating atrial flutter. A contiguous line of bidirectional electrical block is created in the isthmus area between the tricuspid annulus and the inferior vena cava by application of radiofrequency energy. In patients with both atrial flutter and atrial fibrillation, ablation of the atrial flutter circuit may make the atrial fibrillation more easy to control. Quality of life assessments show improvement after ablation of atrial flutter. With a probability of success of 90%, a recurrence rate of 5% to 15%, and few complications, catheter ablation emerges as the best treatment of recurrent, symptomatic flutter.     

Current concepts in diagnosis and treatment of tachyarrhythmias

A diagnostic and therapeutic approach of supraventricular and ventricular tachyarrhythmia is always challenging. Several criteria serve to discriminate correctly between these two types of tachycardia. Cardiac arrhythmias are terminated reliably by intravenous (IV) application of antiarrhythmic drugs: adenosine for supraventricular arrhythmia, amiodarone or ajmaline for ventricular tachycardia. Furthermore, AV-nodal tachycardia, atrioventricular reciprocating tachycardia, and typical atrial flutter is treated curatively by radiofrequency ablation during an electrophysiological study. This interventional therapy is well established in patients suffering from ventricular premature contractions or tachycardia originating in the right or left ventricular outflow tract. Aside treatment with an implantable defibrillator, patients with coronary artery disease highly benefit from adjusted pharmaceutical treatment.     

点消融和线性消融治疗典型心房扑动的对比研究

目的:采用点消融三尖瓣峡部的方法治疗典型心房扑动,并对比常规线性消融,证实点消融治疗典型心房扑动的可行性。方法:14例典型心房扑动病人分为线性消融组(A组)与点消融组(B组),分别比较2组下腔静脉与三尖瓣峡部双向阻滞的手术时间、X线照射时间、放电次数、手术费用、复发率。结果:点消融组病人的手术时间、X线照射时间短,放电次数少,手术费用低(P<0．01),2组均无心包填塞、三度房室传导阻滞以及栓塞等并发症,复发率没有统计学差异。结论:点消融是一种值得进一步推广的治疗典型心房扑动的方法。     

Macroscopic and microscopic study of the right coronary artery after radiofrequency catheter ablation of cavotricuspid isthmus in an experimental model]

INTRODUCTION AND OBJECTIVES: The right coronary artery (RCA) is found in the AV groove, just below the ablation target of atrial flutter, the cavotricuspid isthmus (ICT). After radiofrequency (RF) ablation with standard catheters, there have been no reports of complications, but it may not be successful in 10% of the cases. However, the use of irrigated tip catheters, which create deeper lesions, might potentially damage the coronary tree. METHODS: We analyzed the effects of ICT RF ablation on the coronary tree, with macroscopic and microscopic anatomopathological study. Ablation on ICT was performed using an irrigated tip catheter in 16 pigs and was randomly compared with a standard ablation catheter. There were no clinical problems, modifications of ST or new arrhythmias during the ablation. The heart was extracted at 1 week. RESULTS: The macroscopic study demonstrated that the right coronary artery was preserved, along the ICT, surrounded by the epicardial fat. The microscopic study showed an inflammatory reaction in the epicardial fat that reached the adventitia of the coronary artery, but never produced necrosis in 14 cases. The muscular wall of the artery had signs of focal inflammation without endothelium involvement in 2 cases. However, we found a subepicardial vein completely damaged by the radiofrequency. CONCLUSIONS: Although the right coronary artery is located just below the isthmus, no necrosis was observed in any case. However, there was an inflammatory reaction that focally reached the muscular wall. The veins may be damaged in RF ablation, perhaps due to the different blood flow of each vessel.     

单导管标测在心房扑动射频消融中的意义

目的:探讨单导管标测法在心房扑动(房扑)射频消融中的应用方法和效果。方法:阵发性心房颤动并发房扑患者行肺静脉电隔离术时采用单导管标测法消融房扑30例。所有患者行肺静脉电隔离术后,将10极冠状静脉窦(CS)导管远端2对电极放置于CS内,余位于CS外,并使之有一定的张力,使导管贴靠于三尖瓣环和低右房。用冷盐水灌注消融导管线性消融三尖瓣峡部,房扑发作患者在房扑下消融,窦律患者在CS远端电极起搏下消融,可在术中随时把大头消融导管置于希氏束部位,用于评价是否已完全达双向阻滞,即:起搏CS远端电极,刺激信号至CS近端电极A波的距离大于至希氏束A波的距离,则CS口至低右房单向阻滞;CS近端电极起搏,刺激信号至CS远端电极A波的距离大于至希氏束A波的距离,则低右房至CS口单向阻滞,从而达双向阻滞,CS近端电极起搏所需电压较高,有的患者可达24mA。结果:所用阵发性心房颤动并发房扑患者均成功行三尖瓣峡部线性射频消融,达到双向阻滞,无手术相关并发症,随访4个月～2年,无房扑复发。结论:单导管标测法对房扑患者行三尖瓣峡部线性射频消融操作简单、快速,可完全用于评价消融结果,成功率高,并且节省手术费用。     

Radiofrequency ablation for cure of atrial flutter

Abstract Background: Atrial flutter is a common arrhythmia which frequently recurs after cardioversion and is relatively difficult to control with antiarrhythmic agents.
Aims: To evaluate the success rate, recurrence rate and safety of radiofrequency (RF) ablation for atrial flutter in a consecutive series of patients with drug refractory chronic or paroxysmal forms of the arrhythmia.
Methods: Electrophysiologic evaluation of atrial flutter included activation mapping with a 20 electrode halo cadieter placed around the tricuspid annulus and entrainment mapping from within the low right atrial isthmus. After confirmation of the arrhythmia mechanism with these techniques, an anatomic approach was used to create a linear lesion between the inferior tricuspid annulus and the eustachian ridge at the anterior margin of the inferior vena cava. In order to demonstrate successful ablation, mapping techniques were employed to show that bi-directional conduction block was present in the low right atrial isthmus.
Results: Successful ablation was achieved in 26/27 patients (96%). In one patient with a grossly enlarged right atrium, isthmus block could not be achieved. Of the 26 patients with successful ablation, mere has been one recurrence of typical flutter (4%) during a mean follow-up period of 5.5±2.7 months. This patient underwent a successful repeat ablation procedure. Of eight patients with documented clinical atrial fibrillation (in addition to atrial flutter) prior to the procedure, five continued to have atrial fibrillation following the ablation. There were no procedural complications and all patients had normal AV conduction at the completion of the ablation.
Conclusions: RF ablation is a highly effective and safe procedure for cure of atrial flutter. In patients with chronic or recurrent forms of atrial flutter RF ablation should be considered as a first line therapeutic option.     

Radiofrequency Ablation of Atrial Flutter

RF Ablation of Atrial Flutter. Activation mapping in common atrial flutter has shown circular (reentrant) activation of the right atrium around anatomic structures and areas of functional block. The direction of rotation is counterclockwise (in a frontal view), and in the low right atrium the myocardium between the inferior vena cava (IVC) and the tricuspid valve (TV) is critical to close the activation circle. The circuit can be interrupted by radiofrequency ablation of the myocardium between the TV and the IVC, and, in some cases, by ablation between the coronary sinus and TV. Flutter interruption does not mean complete isthmus ablation, as it may remain inducible, requiring further ablation. Despite attaining noninducibility, flutter may recur, and new procedures may be needed for complete ablation. Atrial fibrillation occurs in up to 30% of the cases during follow-up but is generally well controlled with antiarrhythmic drugs that were ineffective in treating flutter before ablation. Some noncommon atrial flutters show circular right atrial activation in a reversed (clockwise) direction, with the same critical areas in the low right atrium, and in these isthmus ablation is effective. Other noncommon flutters have different substrates in the right or left atrium, and mapping has to define specific critical isthmuses as ablation targets in each case. Left atrial flutter circuits remain inaccessible to ablation.     

Intracardiac echocardiography during radiofrequency catheter ablation of cardiac arrhythmias in humans

Objectives. The purpose of this study was to describe our preliminary experience using catheter-based intracardiac echocardiography as an adjunct to biplane fluoroscopy for guiding radiofrequency catheter ablation of atrial arrhythmias in the right side of the heart.Background. Catheter ablation requires precise positioning and stable ablation electrode-endocardial contact. This procedure is currently guided by an analysis of intracardiac electrograms and fluoroscopy. However, the use of fluoroscopy does not allow the endocardium and certain anatomic landmarks to be identified and is associated with the hazards of radiation exposure.Methods. Seventeen symptomatic patients were studied. A 10F 10-MHz intracardiac imaging catheter was used to visualize specific anatomic landmarks in the right atrium for directing the ablation electrode in 15 patients undergoing radiofrequency ablation of 19 arrhythmias and to assist with interatrial septal puncture in 3 patients.Results. Continuous intracardiac imaging was performed for a mean ± SD of 63.6 ± 39.2 min and demonstrated distal electrode-endocardial tissue contact in 81 (60%) of 134 radiofrequency applications. Movement of the catheter was demonstrated during 36 (44%), microcavitations during 39 (48%) and thrombus during 15 (19%) of the 81 imaged applications. In 7 of 10 procedures for atrial flutter, successful ablation was directed at anatomic corridors in the right atrium visualized with intracardiac echocardiography. During ablation of atrial tachycardia, imaging identified abnormal atrial anatomy related to previous surgery and guided successful ablation of a reentrant tachycardia circulating around these anatomic obstacles. In two procedures for slow pathway modification of atrioventricular node reentrant tachycardia, intracardiac echocardiography confirmed catheter stability at the tricuspid annulus anterior to the coronary sinus.Conclusions. During catheter ablation, intracardiac echocardiography augments fluoroscopy by visualizing anatomic landmarks, ensuring stable endocardial contact and assisting in transseptal puncture. Ablation of typical atrial flutter can be successfully directed at anatomic corridors identified using intracardiac imaging.     

老年心房颤动不同方式的经导管射频消融治疗

目的研究不同方式经导管射频消融治疗对老年房颤的治疗效果。方法53例房颤患者，男性38例，女性15例，年龄60-83岁。按接受不同的经导管消融方法将上述患者分为3组：消融隔离肺静脉治疗阵发性房颤组20例、消融典型房扑治疗房颤合并房扑组26例、消融房室传导加植入永久性起搏器治疗持续性房颤伴药物难以控制的快速心室率和（或）心力衰竭组7例。结果消融隔离肺静脉组中15例采用环状标测电极导管引导电隔离3～4根肺静脉成功，术后无房颤发作8例（53％），房颤发作明显减少4例（27％）；采用电解剖系统引导下环双侧肺静脉线性消融隔离肺静脉5例，无房颤发作4例（80％）。消融房扑组26例典型房扑均消融成功，随访中15例（58％）无房颤发作，8例（31％）房颤发作较前减少。经导管消融房室传导组7例全部成功，4例行右心室、3例行双心室VVI模式起搏，随访中生活质量和（或）心力衰竭症状明显改善。结论针对不同类型的老年房颤患者采用不同的经导管消融方法可以取得较好的临床效果。